Rabbucks are large lagomorphs from the book After Man: A Zoology of the Future written by Dougal Dixon. 50 million AD, in the Posthomic period, they fill in the niches of deer, most antelope, zebras and even giraffes in part.
Evolution of Rabbucks
During the period immediately before and during the rise of humanity the principal large-scale grazers and browsers were the ungulates, the hoofed mammals. They were generally lightly built running animals, able to escape quickly from predators and with teeth particularly suited to cropping leaves and grasses. The ungulates were widely used by man for his own purposes. Cattle and goats were domesticated for milk and meat, sheep were bred for wool and the skins of many were used for leather. Horses and certain other cattle (called oxen, different from the ones mentioned earlier) were harnessed to work for humans and became the classic beasts of burden. By the time mankind became extinct these particular mammals had become so dependent on humans that they could no longer survive.
The deer, the wild ungulates of the temperate latitudes, fared little better. Vast tracts of temperate woodlands had been destroyed to make room for humanity's cities and to provide agricultural land. This interference with their habitat was so intolerable and put such pressure on the deer that their numbers fell to a level from which they never recovered. What then could take their place? A whole ecological niche was vacant with nothing to exploit it. Which creature was best placed to take the initiative?
During humanity's reign a small-scale grazer was present that was so successful it was considered to be a pest. The rabbit was so seriously destructive of human crops, that humans made numerous attempts to control it and even attempted to exterminate it. Yet no matter what actions he took he never succeeded in getting rid of it completely. After humankind's disappearance, the rabbit's versatility and short breeding cycle enabled it to develop successfully into a number of separate forms. The most successful, the rabbuck, Ungulagus spp., now occupies the niche left by many of the ungulates.
To begin with the rabbuck changed little from its rabbit ancestors excepting for size. In an environment totally devoid of large, hoofed grazing animals the rabbit was left with no major grazing competitors and quickly evolved to occupy the position they once held. The early rabbucks, Macrolagus spp., retained the hopping gait of their forebears and developed
strong hind legs for leaping. However, although jumping was ideal for moving around the open grasslands, their traditional habitat, it was not the best method for the confined spaces of the forest, and a more fundamental change had to take place. Several species of this earlier line still exist, but their place has largely been taken by the running forms of rabbuck that more closely resemble the deer of earlier times.
The second major development took place some 10 million AD. As well as developing rapidly into the size of a deer the rabbucks also began to evolve the
typical deer leg and gait. The jumping hind limbs and the generalized forelimbs of the rabbit grew into long-shanked running legs and the feet changed radically. The outer digits atrophied and the second and third toes grew into hoofs, strong enough to bear the animal's weight. This was a highly satisfactory arrangement and this line has now largely replaced the leaping form as the dominant group.
The rabbuck has been so successful that it is found in a wide variety of forms throughout the world - from the tundra and coniferous forests of the far north to the deserts and rainforests of the tropics.
Species of Rabbuck
Common Rabbuck (Ungulagus silvicultrix)
Arctic Rabbuck (Ungulagus hirsutus)
Desert Rabbuck (Ungulagus flavus):
Mountain Rabbuck (Ungulagus scandens)
Strank (Ungulagus virgatus)
Watoo (Ungulagus cento)
Picktooth (Dolabrodon fossor)
Hopping Rabbucks (Macrolagus spp.)
Additionally, an unidentified rabbuck is seen being attacked by night stalkers on an island in Batavia; it is unknown what species this belongs to, or if is a rabbuck at all.
All rabbucks, whether temperate or tropical, retain the dazzling white tail of their rabbit ancestors. It is used as a warning signal when the herd is attacked.